Method of seasoning condensers



No Drawing.

Patented June 17, 1930 PATENT OFFICE LEON H. RICHMOEND, OF FORT H.G.-WRIGHT,NEW YORK METHOD OF SEASON ING CONDENSEBS This inventionrelates to electric Condensers I particularly those of the type used inradio communication, and has specific relation to the material employedas the dielectric.

The primary object of my invention is to provide a method of treating acondenser in such a manner as to effect a permanent increase in itscapacity and to minimize the coefiicientofchange in capacity with achange in temperature.

It has been discovered that condensers eniploying fibrous dielectrics,such as paper, after ageing for some time, have a capacity greater thanwhen first manufactured. This is particularly true in the rolled type ofpaper condenser. Moreover, the change of capacity is found to be greaterwhen two or more layers of paper are used for insulation than when onlyone layer is employed. This change of capacity takes place even when thecondenser is not exposed to air.

It is therefore proposed to incorporate in the process of manufacture ofthe condenser a method which will prevent this change of capacity withage. Generally, this method is applicable to rolled condensers ofcircular cross section, that is, they have not been subected to anyforming process after being rolled in the usual manner, and consists incausing the condenser topass through cycles of temperature changes. I

Specifically the process consists in exposing the condenser totemperatures as follows:

1. Temperatures ranging from 25 to 45 Fahrenheit for three days.

2. Ordinary temperatures for not less than two days.

3. Temperatures rangin from O to 5 Fahrenheit. b

4. Ordinary temperatures for not less than two days.

6. Ordinary temperatures for not less than two days.

7. Temperatures ranging from 25 to Fahrenheit for three days.

8. Ordinary temperatures for not less than two days.

9. Temperatures ranging from 112 to' Application filed. April 6, 1927.Serial No. 181,615.

115 for forty-eight hours.

10. Room temperatures for'not less than a week before calibrating.

The variations in temperatures over comparatively long periods makeminute changes in the shape of the condenser and the relative positionof the conducting layers, thus giving it a permanent set. The finalraising to a high temperature, namely, 112 to 115 Fah renheit, softensthe dielectric, and by expansion due to heat, causes internal pressureand squeezes all the irregularities out of the di electric, thus makingit a smooth homogeneous sheet.

' The condenser may or 'may not be placed in a covering or containerduring this season ing process. No pressure other than atmosphericpressure and no special equipment is necessary exceptthe means forvarying the temperature and maintaining it within certain limits.Temperatures as high as the melting point of the dielectric (paraflin,wax, or the like) are not employed in this process.

The results actually obtained by the practical application of thisseasoning process are a permanent increase and a minimum coefficient ofchange in capacity of the condenser with a change in temperature; a moreconstant and unchanging power factor; and no permanent change incapacity or power factor due to a change in temperature within limits ofseasonal. changes, ranging approximately from 5 Fahrenheit to 110Fahrenheit.

Having thus described my invention what I claim is 1. The method ofseasoning or treating a condenser after being. rolled in the usualmanner, which method consists in exposing said condenser to a cycle oftemperature changes said cycle of temperature changes being sufiicientto permanently set the electrical capacity of the condenser butinsufficient to melt the elements thereof.

2. The method of seasoning or treating a condenser after being rolled inthe usual manner, which method consists in exposing said condenser to acycle of temperature changes, said cycle consisting of alternate periodsof ordinary temperatures and periods of variant temperaturessubstantially diiferit-b5...

ing from said ordinary temperatures but insuflicient to melt thecondenser elementssaid periods of temperature variations bein arrangedto cause a permanent fixing o the I 1 electrical capacity of thecondenser.

3. The method of seasoning or treating a condenser after being rolled inthe usual manner, which method consists in exposing said condenser to acycle of'temperature changes, said cycle consisting of alternate periodsof ordinary temperatures and periods of temperatures substantiallydifiering from said ordinary temperatures, the last period of saiddiflering temperatures being a temperature considerably in excess indegree to the other temperatures but less than the melting temperatureof the condenser elements.

4. The method of effecting an increased and constant capacity in acondenser, which method consists in exposing said condenser to a seriesof temperature changes which a1- ternately vary from ordinarytemperatures to temperatures difi'ering sufliciently from said ordinarytemperatures to set the elements of the condenser but insuflicient tocause fusion of the elements.

5. The method of seasoning or treating a condenser after having beenrolled in the usual manner, which method consists in subjecting' saidcondenser to a cycle of temperature changes, including in sequencetemperatures ranging from 25 to 45 Fahrenheit; ordinary temperatures;temperatures ranging from 0 to 5 Fahrenheit; ordinary temperatures;temperatures ranging from to- Fahrenheit; ordinary temperatures;temperatures ranging from 25 to 45 Fahrenheit; ordinary temperatures;temperatures ranging from 112 to Fahrenheit; room temperatures.

6. The method of seasoning dr treating a I condenser after having beenrolled in the usual manner, which vmethod consists in sub-. ect1ng saidcondenser to a cycle of temperature changes, including in sequencetemperatures ranging from 25 to 45 Fahrenheit for Y three days; ordinarytemperatures for not less than two days; temperatures ranging from 0 to5 Fahrenheit for forty-eight hours; ordinary temperatures for not lessthan'two days; temperatures ranging from .90 to 100 Fahrenheit forforty-eight hours;

. ordinary temperatures for not less than two days;temperaturesranging'fro m 25 to 45 Fahrenheit for three days; ordinarytemperatures for not less than twodays; temper'a tures ranging from 112tog115 Fahrenheit for forty-eight hours and room temperatures for notless than a week before calibrating.

In testimony whereof I afiix my si ature.

LEON H. RICHMOND.

